JP2008099431A - Method and apparatus for information processing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an information processing method that assists in planning measures to prevent overcontrol. <P>SOLUTION: The information processing method is for simulating load frequency control in an electric power system. An information processor 10 having CPU 11 and a memory 12 determines an LFC (Load Frequency Control) control amount, or an amount of control in load frequency control, based on an inputted present amount AR (Area Requirement) of area requiring power. The LFC control amount is allocated to each generator constructing an electric power system to generate a command value for each generator, and a generator output, or the total sum of power outputted from each generator, is determined. The present amount AR of area requiring power is fed back as an input for determining an LFC control amount. The relation between the amount of change in area requiring power amount AR and the cumulative value of amount of change in generator output when a condition for the allocation of the LFC control amount is changed is determined. The correspondence between the area requiring power amount AR, the cumulative value of amount of change, and a determined period of endurance is output. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a technique for simulating load frequency control in an electric power system, and relates to an information processing method and an information processing apparatus that support planning of measures for preventing overcontrol of a generator.

With the recent liberalization of electric power, maintenance of electric power quality has become an issue for electric power companies. Here, as one of the elements that determine the power quality, there is load frequency control (LFC) that observes the frequency in the power system and feeds it back to the power generation amount in the power system. In load frequency control, for a load with a fluctuation cycle of several minutes to several tens of minutes, a command value obtained by adding an area requirement AR (Area Requirement) representing the supply and demand difference of the power system to the output of the current generator is given to the generator. By sending it, the supply and demand balance is achieved (see, for example, Patent Document 1).
JP 2001-86649 A JP-A-60-168914

  By the way, when the above command value for load frequency control is frequently sent out, the generator becomes so-called over-control, which promotes the consumption of the components of the generator and its peripheral devices and shortens the service life. Become. Specifically, for example, a bearing of a guide vane that is a constituent element of a hydroelectric generator has a predetermined service life and needs to be replaced when wear progresses (see, for example, Patent Document 2). If the generator is over-controlled frequently due to the command value, the work burden and cost burden for inspection and replacement will increase.

  Here, in order to prevent such over-control, for example, it is conceivable to slow down the command value sent to the generator. However, in this case, it is necessary to prevent the change in the command value from affecting the regional requirement AR, and when measures are taken against overcontrol, it is necessary to examine the effect on the entire power system.

  The present invention has been made in view of such a background, and an object thereof is to provide an information processing method and an information processing apparatus for simulating load frequency control in a power system that supports planning of measures for preventing overcontrol. To do.

  In order to achieve the above object, an invention according to claim 1 is an information processing method for simulating load frequency control in an electric power system, wherein an information processing device having a CPU and a memory is inputted as a current local requirement amount. A step of obtaining an LFC control amount that is a control amount of load frequency control based on AR, and generating a command value for each generator by allocating the LFC control amount to each generator constituting the power system. A step of obtaining a generator output that is a sum of electric power output from each of the generators, a step of feeding back the current regional requirement amount AR as an input in the step of obtaining the LFC control amount, and the LFC A change amount of the regional requirement amount AR and a cumulative value of the change amount of the generator output when the condition for distributing the control amount is changed. And to include a step of obtaining the engagement.

  According to the present invention, in the power system in which load frequency control is performed, the amount of change in the regional requirement amount AR when the distribution condition of each generator of the LFC control amount generated based on the regional requirement amount AR is changed. And the cumulative value of the change amount of the generator output can be known. For this reason, it is possible to know the influence of the change in the accumulated value of the change amount of the generator output on the regional requirement amount AR, and it is possible to provide information useful for planning measures for preventing overcontrol.

  Note that the change amount of the regional requirement amount AR is obtained as an increase amount with respect to the regional requirement amount AR when the distribution condition is not changed, for example. The distribution conditions include, for example, restrictions on the changing speed of each generator, whether to permit redistribution of the LFC control amount for each generator, and the like. The step of obtaining the LFC control amount includes, for example, a step of removing an extremely short period component from the current local requirement amount AR inputted, a step of removing a fine movement component from the regional requirement amount AR, And performing a PID calculation. The step of obtaining the generator output includes, for example, a step of simulating constraints on the upper and lower limits of the output of each generator in the input command value, and a step of simulating constraints on the change rate of each generator in the input command value And a step of performing first-order lag processing on the input command value.

  Further, another main invention of the present invention is based on the step in which the information processing apparatus outputs the relationship between the change amount accumulated value and the consumption amount of the constituent elements of the generator, and the relationship between the change amount accumulated value and the consumption amount. The method further includes the step of obtaining the useful life of the component, and storing the correspondence between the regional requirement amount AR, the accumulated change amount, and the obtained useful life.

  The constituent element of the generator is, for example, a guide vane used for hydroelectric power generation, and the consumption amount is the wear amount of the guide vane.

  Thus, according to the present invention, it is possible to easily know the relationship between the accumulated amount of change when the distribution condition is changed and the useful life of the constituent elements of the generator such as the guide vane.

  Another main invention of the present invention is an information processing apparatus for simulating load frequency control in an electric power system, having a CPU and a memory, and a control amount of load frequency control based on an inputted current local requirement AR. Means for determining the LFC control amount, means for generating a command value for each generator by allocating the LFC control amount to each generator constituting the power system, and output from each generator A means for obtaining a generator output that is a sum of generated electric power, a means for feeding back the current regional requirement amount AR as an input in the step of obtaining the LFC control amount, and changing the condition of the distribution of the LFC control amount Means for determining the relationship between the change amount of the regional requirement amount AR and the cumulative value of the change amount of the generator output.

  According to the information processing method and the information processing apparatus of the present invention, it is possible to support the planning of measures for preventing the generator from being overcontrolled by the load frequency control.

  Hereinafter, one embodiment of the present invention will be described in detail. FIG. 1 illustrates a hardware configuration of an information processing apparatus 10 that performs a simulation (simulation) of load frequency control in an electric power system, which is described as an embodiment of the present invention.

  An information processing apparatus 10 shown in FIG. 1 is a computer such as a personal computer, a workstation, or a main frame, for example. As shown in the figure, an information processing apparatus 10 includes a CPU 11, a memory 12 such as a RAM / ROM, a hard disk 13, an input device 14 such as a keyboard and a mouse, a display device 15 such as a liquid crystal display, a LAN (Local Area Network), and the like. A communication interface 16 for connecting to the communication network is provided.

  FIG. 2 shows functions related to the simulation provided by the information processing apparatus 10. Each function shown in the figure is realized by a function of hardware constituting the information processing apparatus 10 or when the CPU 11 executes a program stored in the memory 12 or the hard disk 13.

In FIG. 2, an automatic power supply system 21 simulates a system that performs maintenance management of an electric power system that operates in a central power supply command center of an electric power company. The automatic power feeding system 21 receives a regional request amount AR fed back from an adder 25 described later. The automatic power supply system 21 generates a command value for generator output control to be sent to a generator block 22 to be described later, according to the input regional requirement amount AR.
Note that, in the present embodiment, the regional demand AR is defined as the generator output to be subjected to load frequency control and the load of the generator to be subjected to load frequency control (the generator output to be subjected to load frequency control by actual measurement). The difference from the regional requirement AR (according to actual measurement).

  FIG. 3A shows details of the function of the automatic power feeding system 21. The regional requirement amount AR input as feedback is first input to the smoothing processing unit 211, where an extremely short period component is removed. Further, in the next dead zone processing unit 212, the fine movement component included in the regional requirement amount AR is removed. The next PID calculation processing unit 213 (PID: Proportional Integral Differential) generates an LFC control amount by performing PID calculation processing on the regional requirement amount AR.

  The distribution processing unit 214 distributes the generated LFC control amount to each generator in accordance with a condition imposed on each generator (hereinafter referred to as distribution condition). Here, the distribution conditions include, for example, a change speed constraint on the output of each generator and whether redistribution is permitted (presence / absence of redistribution). The command value generation unit 215 adds the output of the current generator block 22 to the LFC control amount output from the distribution processing unit 214 to generate a command value for each generator.

  FIG. 3B shows details of the function of the distribution processing unit 214. The LFC control amount output from the PID calculation processing unit 213 is first distributed by the proportional distribution processing unit 2141 according to a distribution ratio set in advance to each generator. The next change rate constraint processing unit 2142 imposes a change rate constraint on the LFC control amount allocated to each generator. Further, the redistribution processing unit 2143 redistributes the surplus power that could not be allocated to each generator due to the change speed constraint to another generator having a sufficient output. The upper and lower limit constraint processing unit 2144 imposes mechanical operation constraints on the generator on each LFC control amount allocated to each generator.

  The generator block 22 shown in FIG. 2 simulates the operation of each generator constituting the power system. The generator block 22 generates a generator output based on the control command value output from the automatic power feeding system 21 and the measured command value 23 stored in the memory 12 or the hard disk 13. FIG. 3C shows details of the function of the generator block 22. In the figure, an upper / lower limit constraint processing unit 221 simulates upper / lower limit constraints imposed on each generator. The rate-of-change constraint processing unit 222 simulates constraints on the rate of change of output imposed on each generator.

The total measured demand 24 shown in FIG. 2 is the sum of the actually measured load and the actually measured local demand (hereinafter referred to as “measured AR”). The actually measured load and the actually measured AR are stored in the memory 12 or the hard disk 13. The adding unit 25 shown in FIG. 2 adds the generator output (negative value) output from the generator block 22 and the measured total demand 24 (positive value), and calculates the measured total demand 24 and the generator output. Calculate the difference. Note that the difference between the calculated actual measured demand 24 and the generator output is the regional requirement amount AR that is fed back to the automatic power supply system 21.

The cumulative value calculation block 26 in FIG. 2 generates a cumulative value of the change amount of the generator output (hereinafter referred to as a change amount cumulative value ΔWtotal) based on the generator output output from the generator block 22. The change amount cumulative value ΔWtotal is obtained by summing up absolute values of output changes at each sampling interval in a time zone in which each generator is a control target of load frequency control. For example, in the example shown in FIG. 4, the change amount cumulative value ΔWtotal at times t _{1 to} t ₄ is
ΔWtotal = | ΔW ₁ | + | ΔW ₂ | + | ΔW ₃ |
As required.

  The evaluation processing unit 27 in FIG. 2 changes the redistribution condition based on the regional requirement amount AR output from the addition unit 25 and the change amount cumulative value ΔWtotal output from the cumulative value calculation block 26. The change amount of the regional requirement amount AR output from the addition unit 25 with respect to the regional requirement amount AR and the change amount accumulated value ΔWtotal output from the addition unit 25 when the redistribution condition is not changed in the plurality of cases, A change amount of the change amount cumulative value ΔWtotal is obtained. Table 1 shows an example of the above case. In Table 1, the change rate constraint in each case is shown with the change rate constraint in the case of mounting simulation being 100%.

Case 1 is a case where the change rate constraint is 50% and redistribution by the redistribution processing unit 2143 is not permitted (redistribution: none). Case 2 is a case where the change rate constraint is 20% and redistribution is not permitted (redistribution: none). Case 3 is a case where the change rate constraint is 50% and redistribution is not permitted (redistribution: none).
In case 3, the command value output from the automatic power feeding system 21 is further provided to the generator block 22 through a low pass filter (LPF: present).

  Table 2 shows the results of simulation performed for each case in Table 1. In Table 2, the change amount of the regional requirement amount AR is indicated by a standard deviation (hereinafter referred to as AR standard deviation) when the regional requirement amount AR in the actual simulation is 100%.

  As can be seen from Table 2, even if the change amount cumulative value ΔWtotal changes (100% (actual simulation) → 55% (case 1) → 28% (case 2) → 25% (case 3)), AR It can be seen that the standard deviation hardly changes. Also, from the result of Case 3, when the command value is given through the low-pass filter, even if the change speed constraint is 50% (see Table 1), the change amount is accumulated without affecting the AR standard deviation. It can be seen that the value ΔWtotal can be suppressed to 25%.

  On the other hand, in addition to the relationship between the AR standard deviation and the change amount accumulated value ΔWtotal, the evaluation processing unit 27 stores the change amount accumulated value ΔWtotal for each generator stored in the memory 12 or the hard disk 13 and the hydraulic power of the hydroelectric power plant. The service life N of the guide vane is determined based on the relationship with the wear amount ΔX of the guide vane that is a component of the generator.

  FIG. 5 shows an example of the relationship between the change amount cumulative value ΔWtotal and the guide vane wear amount ΔX for a generator constituting the power system. In the example shown in the figure, the relationship between the change amount cumulative value ΔWtotal and the wear amount ΔX is linear (linear function).

  Here, for example, when the limit value ΔXmax of the wear amount is 5 mm, the change amount accumulated value ΔWtotal of the actually measured simulation corresponding to this is 100 kW, and the corresponding service life N is 3 years, the service life N is If it is assumed that the wear amount limit value ΔXmax is inversely proportional to the wear amount limit value ΔXmax, the change amount accumulated value ΔWtotal is 55 kW in Case 1 (55% if the actual simulation is 100%), so the service life N is 3 years × (100/55) ≈ 5 years is required. In case 2, the change amount cumulative value ΔWtotal is 28 kW (28% if the actual simulation is 100%), so the useful life N in this case is 3 years × (100/28) ≈about 10 years. The guide vane estimated life shown in Table 2 is obtained as described above.

  The information processing apparatus 10 appropriately displays the contents of Table 2 on the display device 15 and provides them to the user of the information processing apparatus 10. For this reason, the user can easily grasp the change of the AR standard deviation and the change of the service life of the guide vane with respect to the change of the change amount cumulative value ΔWtotal, and the user can refer to this and take measures to prevent overcontrol. Can be useful for planning.

  By the way, description of the above embodiment is for making an understanding of this invention easy, and does not limit this invention. It goes without saying that the present invention can be changed and improved without departing from the gist thereof, and that the present invention includes equivalents thereof.

  For example, in the above embodiment, the guide vanes of the hydroelectric generator are taken up as an example of the constituent elements of the generator. However, the present invention is widely applied to the constituent elements of the generator in which the speed of wear changes by load frequency control. Can be applied. Further, the constituent elements are not limited to the constituent elements of the generator itself, but may be constituent elements of a peripheral device of the generator.

It is a figure which shows the hardware constitutions of the information processing apparatus 10 demonstrated as one Embodiment of this invention. It is a figure which shows the function provided by the information processing apparatus 10 demonstrated as one Embodiment of this invention. It is a figure which shows the detail of the function of the automatic electric power feeding system 21 demonstrated as one Embodiment of this invention. It is a figure which shows the detail of the function of the distribution process part 214 demonstrated as one Embodiment of this invention. It is a figure which shows the detail of the function of the generator block 22 demonstrated as one Embodiment of this invention. It is a figure explaining the calculation method of variation | change_quantity accumulated value (DELTA) Wtotal demonstrated as one Embodiment of this invention. It is a figure which shows an example of the relationship between the variation | change_quantity accumulated value (DELTA) Wtotal about the certain generator which comprises the electric power system demonstrated as one Embodiment of this invention, and the wear amount (DELTA) X of a guide vane.

Explanation of symbols

10 Information processing apparatus 11 CPU
DESCRIPTION OF SYMBOLS 12 Memory 13 Hard disk 21 Automatic power supply system 211 Smoothing process part 212 Dead zone process part 213 PID calculation process part 214 Distribution process part 2141 Proportional distribution process part 2142 Change rate restriction | limiting part 2143 Redistribution process part 2144 Upper / lower limit restriction | limiting part 215 Command Value generator 22 Generator block 221 Upper / lower limit constraint processor 222 Change rate constraint processor 23 Actual command value 24 Actual gross demand 25 Adder 26 Cumulative value calculation block 27 Evaluation processor

Claims (9)

An information processing method for simulating load frequency control in a power system,
An information processing apparatus having a CPU and a memory is provided.
Obtaining an LFC control amount that is a control amount of load frequency control based on the current regional request amount AR inputted;
Generating a command value for each generator by allocating the LFC control amount to each generator constituting a power system;
Obtaining a generator output that is a sum of electric power output from each of the generators;
Feeding back the current regional requirement amount AR as an input in the step of obtaining the LFC control amount;
Obtaining a relationship between a change amount of the regional requirement amount AR and a cumulative value of the change amount of the generator output when the condition for distributing the LFC control amount is changed;
An information processing method characterized by comprising: An information processing method according to claim 1,
An information processing method characterized in that a change amount of the regional requirement amount AR is obtained as an increase amount with respect to the regional requirement amount AR when the distribution condition is not changed. An information processing method according to claim 1,
The information distribution method according to claim 1, wherein the distribution condition is a restriction on a change speed of each generator. An information processing method according to claim 1,
The information distribution method is characterized in that the condition for distribution is whether or not redistribution of the LFC control amount is permitted for each of the generators. An information processing method according to claim 1,
The information processing apparatus is
Storing the relationship between the change amount cumulative value and the consumption amount of the components of the generator;
Obtaining a useful life of the component based on the relationship between the change amount cumulative value and the consumption amount;
An information processing method, further comprising: outputting a correspondence between the regional requirement amount AR, the change amount cumulative value, and the obtained lifetime. An information processing method according to claim 5,
The component of the generator is a guide vane used for hydroelectric power generation,
The information processing method, wherein the consumption amount is an abrasion amount of the guide vane. An information processing method according to claim 1,
The step of obtaining the LFC control amount includes:
Removing an extremely short period component from the inputted current local requirement AR;
Removing fine movement components from the regional requirement AR;
Performing a PID operation on the regional requirement amount AR. An information processing method according to claim 1,
The step of obtaining the generator output comprises:
Simulating constraints on the upper and lower limits of the output of each generator in the command value that is input;
Simulating constraints on the rate of change of each of the generators in the input command value;
And a step of performing first-order lag processing on the input command value. An information processing apparatus for simulating load frequency control in a power system,
CPU and memory
Means for obtaining an LFC control amount that is a control amount of the load frequency control based on the input current local requirement amount AR;
Means for generating a command value for each generator by allocating the LFC control amount to each generator constituting the power system;
Means for determining a generator output that is a sum of electric power output from each of the generators;
Means for feeding back the current regional requirement amount AR as an input in the step of obtaining the LFC control amount;
Means for obtaining a relationship between a change amount of the regional requirement amount AR and a cumulative value of the change amount of the generator output when the distribution condition is changed;
An information processing apparatus characterized by including:

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